import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * Created By  醉美柳舞之众星捧月
 *
 * @author songx
 * @date 2018/10/7 18:25
 */
public class Test {
    public static void main(String[] args) {
        String a = "songxiankun";
        String b = new String("songxiankun");
        String c = "song" + "xian" + "kun";
        System.out.println(a == b);
        System.out.println(a == c);
        System.out.println(b == c);
        String home = System.getenv("JAVA_HOME");
        System.out.println(home);
        System.out.println("---------------------------------------------split----------------------------------------------------");
        Map<String, String> map = System.getenv();
        Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }
        System.out.println("---------------------------------------------split   2    ----------------------------------------------------");
        Properties properties = System.getProperties();
        Iterator<Map.Entry<Object, Object>> entryIterator = properties.entrySet().iterator();
        while (entryIterator.hasNext()) {
            System.out.println(entryIterator.next());
        }
        Calendar instance = Calendar.getInstance();
        Date time = instance.getTime();
        System.out.println(time);
        System.out.println(instance.getActualMaximum(Calendar.DAY_OF_MONTH));
        ArrayList list = new ArrayList();
        Iterator<Object> iterator1 = list.iterator();
        while (iterator1.hasNext()) {
            System.out.println(iterator1.next());
        }
        CopyOnWriteArrayList<Object> copy = new CopyOnWriteArrayList();
        Iterator<Object> iterator2 = copy.iterator();
        while (iterator2.hasNext()) {
            System.out.println(iterator2.next());
        }
        int[] ints = new int[5];
        HashMap map1 = new HashMap();
        ArrayList objects = new ArrayList();
        Arrays.sort(ints);
        Collections.sort(objects);
        Thread thread = new Thread();
        thread.setName("线程一！");
        final ArrayList list1 = new ArrayList();
        list1.add("sdasfsd4584g");
        String lalalalala = "asd485".trim().substring(1, 6);
        lalalalala.intern();
        String s = new String("啦啦啦").intern();
        String lalala = String.valueOf("lalala");
        lalala.intern();
        int integer = Integer.valueOf("123");
        System.out.println(integer);
        List<String> simpleList = List.of("Hello", "world");
        HashMap<Object, Object> map2 = new HashMap<>();
        new LinkedHashMap<>();
    }
}